99 cobra dyno #'s are in (please take a look)

[4chevy2nv]

went to the dyno today and got in 5 runs.

run 1
HP286.6 / TQ285.9
This run was done with about a 30 min cool down, and uncorrected but the SAE was 286.0hp / 285.0tq.

run 2
HP288.0 / TQ289.4
This run was done with a 5 min cool down and they are SAE,

run 3
HP288.8 / TQ291.1
This was done with a 10 min cool down and are SAE.

run 4
HP291.2TQ290.3
This was done with no cool down and is SAE.

run 5
HP290.9TQ288.1
This was run was also done with no cool down and is SAE.

I will post the links to the graghs as soon as my cousin scans them in, and i also got the A/F charts too for you guys to take a look at and, tell me what needs to be done.

The guy at the dyno told me it's running a little rich.

Overall i'm very please with what it dynoed at, taking of 6-7 HP & TQ for the gears, and the h-pipe being the only power mod, im only a couple of mods short of 300HP & TQ.

 

[4chevy2nv]

here are the graghs for the runs, do you guy's think i need help anywhere?


http://y42.photos.yahoo.com/bc/sweetness06516/lst?.dir=/My+Photos

 

[icehoc8]

Did you get a dyno for your cobra stock? How much do dyno's run? So do you think FORD'S FIX did the trick? Thanks

 

[DCMustang00]

I am going to use these numbers to show someone that the Cobra can put down 280 HP

 

[AmdMAN]

Question?

No offense man but last time I checked Gears didn't add any HP. Gears let you get to your max horsepower quicker, but do not give you any HP. So take back the 6-7HP for gears. All you got is the H-Pipe.

 

[tms217]

my 100% stock 01 Cobra put down 275.5HP and 282.1TQ 100% stock minus air silencer. This includes stock airfilter. I think cold air kit and underdrives should give me 300 RWHP.

Terry

 

[CbrCpe]

...This run was done with about a 30 min cool down, and uncorrected but the SAE was....

...you should dyno with CORRECTED SAE, so you can compare with other dyno numbers...apples to apples......SAE CORRECTED corrrects to pressure=29.23 in/hg./tempature=77*F,humidity=0...your gears will not cost you 6-7rwhp...IMO, maybe 2-3 hp...neverless, looks like pretty good numbers...mine stock,dynoed @280.1/290.0 SAE Corrected...

 

[isdnmatt]

Re: Question?

Originally posted by AmdMAN
No offense man but last time I checked Gears didn't add any HP. Gears let you get to your max horsepower quicker, but do not give you any HP. So take back the 6-7HP for gears. All you got is the H-Pipe.

I think he meant that gears take that much HP away from the dyno.

That's what happend to me. The car dynoed stock at 292 HP and after the gears and an O/R H it came down to where it is now (see sig.).

-Matt

 

[AmdMAN]

oh ok.. I get it now..but why would the cost you so much HP?

 

[isdnmatt]

Dynojet used to have information up about the different. It's just the measurement that causes the difference.

 

[CbrCpe]

...last summer this question about gears v. rwhp on a dynojet came up, so I emailed dynojet and ask them...

"If you go to a lower differential gear ratio (ie; 3.27's to 4.10's), will the rwhp numbers be lower, and why?"

He gave a couple of examples and two reasons...(1)rotational mass & (2) rate of acceleration...here is a copy of the email reply, straight for the horse's mouth...

The reason the dyno will show less horsepower with a change to a larger
wheel is because it typically increases the rotational mass. One of the
best scenarios is the guy who puts the monster mudders on his 1982 Toyota
Pickup 4X4 with a four-cylinder engine. The vehicle has a very hard time
trying to accelerate the drastic change in mass due to the larger wheels
and tires. The reason there is a horsepower loss on the dyno is because
more horsepower is being absorbed in trying to get that added mass moving
or spinning, the same as what would happen on the street. The principal is
similar in a gear change. The gear change is much more desirable because
the multiplication of torque involved is a way better improvement than the
small horsepower loss that occurs. The change in gear ratio has two
factors that can affect horsepower. The first is what was covered above
about added mass. The second is rate of acceleration. If the rate of
acceleration is faster due to a lower gear ratio change (2:70 high to 4:10
low), than the horsepower will be less. The reason is because the RPM
limit of the motor is met faster and the horsepower is being absorbed in
trying to accelerate the mass quicker. The reason the rate of acceleration
is increased is because the torque multiplication was increased giving us
more torque, which again, causes harder and quicker acceleration but the
run is over because of the RPM limit before the horsepower can overcome the
spinning up of the mass. The reason Dynojet chooses to show these
differences is because when you are comparing things like carbon fiber
drive shafts versus steel, you will be able to see the added benefit of
this change by being able to see the added horsepower. Dynojet is simply
showing you the change in your vehicle, as close as possible, as it will
occur on the street. After having said all of this, please keep in mind
that your engine's horsepower doesn't change because of the above mentioned
scenarios but what does change is the way the horsepower is used by the
drive train to get it to the rear wheels which is commonly referred to as
drive train loss. The ability to see engine and drive train components and
the effect they have when tuned and matched correctly is what makes the
chassis dyno such a valuable tool.

Shawn Arnold
VP Sales and Technical Support
Dynojet Research, Inc.
702-639-1105
http://www.dynojet.com

 

[AmdMAN]

Originally posted by CbrCpe
...last summer this question about gears v. rwhp on a dynojet came up, so I emailed dynojet and ask them...

"If you go to a lower differential gear ratio (ie; 3.27's to 4.10's), will the rwhp numbers be lower, and why?"

He gave a couple of examples and two reasons...(1)rotational mass & (2) rate of acceleration...here is a copy of the email reply, straight for the horse's mouth...

Hey man thanks for the information. It really helped.